1. Field of the Invention
This invention relates to a disconnectable collimation assembly which makes it possible to ensure access to any optical component requiring a separation between fibers without producing excessive attenuation.
2. Description of the Prior Art
It is often necessary to break an optical line in order to insert systems for switching, picking up, injecting or attenuating signals. The direct use of the light emanating from an optical fiber is awkward. As a matter of fact, the beams are then divergent and the insertion of the systems is obtained at the cost of high losses and of mechanical precision. For example, the act of longitudinally separating two fibers with a diameter of 50/125.mu. by a distance of 7.mu. results in a loss of 0.5 dB as well as an angular misalignment of 1.5 degrees. To separate the ends of the fibers in a consistent fashion, it is sufficient to collimate the beams between two lenses of the plano-convex type, the ends of the fibers being placed at the respective focal point of each lens. With these conditions, the front face of the lenses can be separated by about 30 mm. With the use of lenses of the glass bar type, the insertion loss is then 1.5 db for fibers of 50/125.mu.. This system tolerates an axial misalignment on the order of 0.1 mm and admits of a less precise embodiment. But the system remains as sensitive as the direct fiber-to-fiber connection with respect to angular misalignment.
Due to this sensitivity of the angular alignment, known devices are non-removable, one-piece optical points permanently inserted in the system, and require factory adjustment of the fiber-lens coupling. The manufacturers of optical equipment generally provide their components equipped with a certain length of optical fiber (commonly called a "pig-tail" in the art), which prevents the users from easily creating their own collimation assembly. There also exists an embodiment of disconnectable optical points but they are always integrated in the body of a specific component.
It would be desirable to provide a disconnectable collimate assembly which did not have the above disadvantages.